====================================================== WARNING: possible circular locking dependency detected 6.1.89-syzkaller #0 Not tainted ------------------------------------------------------ udevd/3557 is trying to acquire lock: ffff8880b9828118 (krc.lock){..-.}-{2:2}, at: krc_this_cpu_lock kernel/rcu/tree.c:2990 [inline] ffff8880b9828118 (krc.lock){..-.}-{2:2}, at: add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3310 [inline] ffff8880b9828118 (krc.lock){..-.}-{2:2}, at: kvfree_call_rcu+0x1b2/0x8c0 kernel/rcu/tree.c:3401 but task is already holding lock: ffff888077355a38 (&trie->lock){..-.}-{2:2}, at: trie_delete_elem+0x90/0x690 kernel/bpf/lpm_trie.c:451 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&trie->lock){..-.}-{2:2}: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 trie_delete_elem+0x90/0x690 kernel/bpf/lpm_trie.c:451 0xffffffffa0001fdd bpf_dispatcher_nop_func include/linux/bpf.h:989 [inline] __bpf_prog_run include/linux/filter.h:603 [inline] bpf_prog_run include/linux/filter.h:610 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2273 [inline] bpf_trace_run3+0x231/0x440 kernel/trace/bpf_trace.c:2313 __traceiter_timer_start+0x79/0xd0 include/trace/events/timer.h:53 trace_timer_start include/trace/events/timer.h:53 [inline] enqueue_timer+0x440/0x600 kernel/time/timer.c:609 __mod_timer+0x92b/0xee0 sk_reset_timer+0x1f/0xb0 net/core/sock.c:3370 tipc_sk_finish_conn+0x162/0x810 net/tipc/socket.c:1675 tipc_socketpair+0x253/0x4a0 net/tipc/socket.c:3350 __sys_socketpair+0x402/0x700 net/socket.c:1745 __do_sys_socketpair net/socket.c:1781 [inline] __se_sys_socketpair net/socket.c:1778 [inline] __x64_sys_socketpair+0x97/0xb0 net/socket.c:1778 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #1 (&base->lock){-.-.}-{2:2}: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 lock_timer_base+0x120/0x260 kernel/time/timer.c:999 __mod_timer+0x1cb/0xee0 kernel/time/timer.c:1072 queue_delayed_work_on+0x156/0x250 kernel/workqueue.c:1704 queue_delayed_work include/linux/workqueue.h:527 [inline] schedule_delayed_monitor_work kernel/rcu/tree.c:3171 [inline] kvfree_call_rcu+0x520/0x8c0 kernel/rcu/tree.c:3427 rtnl_register_internal+0x489/0x580 net/core/rtnetlink.c:260 rtnl_register+0x32/0x70 net/core/rtnetlink.c:310 ip_rt_init+0x335/0x3c7 net/ipv4/route.c:3766 ip_init+0xa/0x14 net/ipv4/ip_output.c:1767 inet_init+0x2ae/0x3c0 net/ipv4/af_inet.c:2031 do_one_initcall+0x265/0x8f0 init/main.c:1299 do_initcall_level+0x157/0x207 init/main.c:1372 do_initcalls+0x49/0x86 init/main.c:1388 kernel_init_freeable+0x45c/0x60f init/main.c:1627 kernel_init+0x19/0x290 init/main.c:1515 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 -> #0 (krc.lock){..-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 krc_this_cpu_lock kernel/rcu/tree.c:2990 [inline] add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3310 [inline] kvfree_call_rcu+0x1b2/0x8c0 kernel/rcu/tree.c:3401 trie_delete_elem+0x520/0x690 bpf_prog_8c8ab8634bca3061+0x3a/0x44 bpf_dispatcher_nop_func include/linux/bpf.h:989 [inline] __bpf_prog_run include/linux/filter.h:603 [inline] bpf_prog_run include/linux/filter.h:610 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2273 [inline] bpf_trace_run2+0x1fd/0x410 kernel/trace/bpf_trace.c:2312 __bpf_trace_kfree+0x6e/0x90 include/trace/events/kmem.h:94 trace_kfree include/trace/events/kmem.h:94 [inline] kfree+0xf6/0x190 mm/slab_common.c:994 tomoyo_realpath_from_path+0xbe/0x5d0 security/tomoyo/realpath.c:250 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x29f/0x710 security/tomoyo/file.c:822 security_inode_getattr+0xcf/0x120 security/security.c:1361 vfs_getattr+0x26/0x360 fs/stat.c:158 vfs_statx+0x194/0x4b0 fs/stat.c:233 vfs_fstatat fs/stat.c:267 [inline] __do_sys_newfstatat fs/stat.c:437 [inline] __se_sys_newfstatat fs/stat.c:431 [inline] __x64_sys_newfstatat+0x151/0x1e0 fs/stat.c:431 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 other info that might help us debug this: Chain exists of: krc.lock --> &base->lock --> &trie->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&trie->lock); lock(&base->lock); lock(&trie->lock); lock(krc.lock); *** DEADLOCK *** 3 locks held by udevd/3557: #0: ffffffff8d718c48 (tomoyo_ss){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8d718c48 (tomoyo_ss){....}-{0:0}, at: srcu_read_lock include/linux/srcu.h:165 [inline] #0: ffffffff8d718c48 (tomoyo_ss){....}-{0:0}, at: tomoyo_read_lock security/tomoyo/common.h:1110 [inline] #0: ffffffff8d718c48 (tomoyo_ss){....}-{0:0}, at: tomoyo_path_perm+0x272/0x710 security/tomoyo/file.c:821 #1: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #1: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #1: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2272 [inline] #1: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x110/0x410 kernel/trace/bpf_trace.c:2312 #2: ffff888077355a38 (&trie->lock){..-.}-{2:2}, at: trie_delete_elem+0x90/0x690 kernel/bpf/lpm_trie.c:451 stack backtrace: CPU: 0 PID: 3557 Comm: udevd Not tainted 6.1.89-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 krc_this_cpu_lock kernel/rcu/tree.c:2990 [inline] add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3310 [inline] kvfree_call_rcu+0x1b2/0x8c0 kernel/rcu/tree.c:3401 trie_delete_elem+0x520/0x690 bpf_prog_8c8ab8634bca3061+0x3a/0x44 bpf_dispatcher_nop_func include/linux/bpf.h:989 [inline] __bpf_prog_run include/linux/filter.h:603 [inline] bpf_prog_run include/linux/filter.h:610 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2273 [inline] bpf_trace_run2+0x1fd/0x410 kernel/trace/bpf_trace.c:2312 __bpf_trace_kfree+0x6e/0x90 include/trace/events/kmem.h:94 trace_kfree include/trace/events/kmem.h:94 [inline] kfree+0xf6/0x190 mm/slab_common.c:994 tomoyo_realpath_from_path+0xbe/0x5d0 security/tomoyo/realpath.c:250 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x29f/0x710 security/tomoyo/file.c:822 security_inode_getattr+0xcf/0x120 security/security.c:1361 vfs_getattr+0x26/0x360 fs/stat.c:158 vfs_statx+0x194/0x4b0 fs/stat.c:233 vfs_fstatat fs/stat.c:267 [inline] __do_sys_newfstatat fs/stat.c:437 [inline] __se_sys_newfstatat fs/stat.c:431 [inline] __x64_sys_newfstatat+0x151/0x1e0 fs/stat.c:431 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fc2d2f8e5f4 Code: 64 c7 00 09 00 00 00 83 c8 ff c3 48 89 f2 b9 00 01 00 00 48 89 fe bf 9c ff ff ff e9 00 00 00 00 41 89 ca b8 06 01 00 00 0f 05 <45> 31 c0 3d 00 f0 ff ff 76 10 48 8b 15 03 a8 0d 00 f7 d8 41 83 c8 RSP: 002b:00007ffcf9f3cc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 000000000000000f RCX: 00007fc2d2f8e5f4 RDX: 00007ffcf9f3cc78 RSI: 00007ffcf9f3cd47 RDI: 00000000ffffff9c RBP: 00007ffcf9f3dd80 R08: 0000000000000000 R09: 00007ffcf9f3d708 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffcf9f3dd98 R13: 0000000000000000 R14: 0000000000000008 R15: 00005649782e5910